Common rail fuel systems are well known in the art of compression ignition engines. A typical common rail fuel system includes a common fuel rail that supplies fuel injectors for an engine via individual quill tubes. Because of the high pressures involved, some jurisdictions require a double wall containment strategy for capturing leaked fuel. For instance, co-owned U.S. Patent application 2005/0166899 teaches a high pressure line connection strategy for fluidly connecting a common rail to fuel injectors. Common rail fuel systems can be found that utilize either distillate diesel fuel or heavy fuel oil as the fuel medium. Increasingly, industry has turned toward common rail fuel systems as one strategy for improving burn characteristics to reduce the production of undesirable emissions, including NOx, unburnt hydrocarbons and the like in order to relax demands on aftertreatment systems.
Gaseous fuel engines are known for their ability to burn relatively clean relative to their compression ignition engine counterparts. However, gaseous fuels are well known for the difficulty in attaining successful ignition. Some gaseous fuel engines utilize a spark plug, whereas other engines are known for utilizing a small amount of distillate diesel fuel that is compression ignited to in turn ignite a larger charge of gaseous fuel. Practical spatial limitations in and around an engine often make it difficult to find space for all of the plumbing and hardware associated with supplying two different fuels to each combustion chamber. In this regard, Canadian patent 2,635,410 is of interest for teaching a dual fuel connector that relies upon a single quill that includes two different internal passages to facilitate fluid connection to two different fuel inlets of a fuel injector. However, this reference fails to teach a practical strategy for inhibiting fuel leakage between the two different fuels and from either fuel supply to atmosphere where the illustrated tube contacts the fuel injector.
The present disclosure is directed toward one or more of the problems set forth above.